Source code for niworkflows.interfaces.nitransforms

# emacs: -*- mode: python; py-indent-offset: 4; indent-tabs-mode: nil -*-
# vi: set ft=python sts=4 ts=4 sw=4 et:
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# Copyright 2021 The NiPreps Developers <nipreps@gmail.com>
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"""Wrappers of NiTransforms."""

from pathlib import Path

from nipype.interfaces.base import (
    BaseInterfaceInputSpec,
    File,
    InputMultiObject,
    SimpleInterface,
    TraitedSpec,
    isdefined,
    traits,
)

XFM_FMT = {
    '.lta': 'fs',
    '.txt': 'itk',
    '.mat': 'itk',
    '.tfm': 'itk',
}


class _ConcatenateXFMsInputSpec(BaseInterfaceInputSpec):
    in_xfms = InputMultiObject(File(exists=True), desc='input transform piles')
    inverse = traits.Bool(False, usedefault=True, desc='generate inverse')
    out_fmt = traits.Enum('itk', 'fs', usedefault=True, desc='output format')
    reference = File(
        exists=True,
        desc='reference file (only for writing LTA format, if not concatenating another LTA).',
    )
    moving = File(
        exists=True,
        desc='moving file (only for writing LTA format, if not concatenating another LTA).',
    )


class _ConcatenateXFMsOutputSpec(TraitedSpec):
    out_xfm = File(exists=True, desc='output, combined transform')
    out_inv = File(desc='output, combined transform')


[docs] class ConcatenateXFMs(SimpleInterface): """Write a single, flattened transform file.""" input_spec = _ConcatenateXFMsInputSpec output_spec = _ConcatenateXFMsOutputSpec def _run_interface(self, runtime): out_ext = 'lta' if self.inputs.out_fmt == 'fs' else 'tfm' reference = self.inputs.reference if isdefined(self.inputs.reference) else None moving = self.inputs.moving if isdefined(self.inputs.moving) else None out_file = Path(runtime.cwd) / f'out_fwd.{out_ext}' self._results['out_xfm'] = str(out_file) out_inv = None if self.inputs.inverse: out_inv = Path(runtime.cwd) / f'out_inv.{out_ext}' self._results['out_inv'] = str(out_inv) concatenate_xfms( self.inputs.in_xfms, out_file, out_inv, reference=reference, moving=moving, fmt=self.inputs.out_fmt, ) return runtime
[docs] def concatenate_xfms(in_files, out_file, out_inv=None, reference=None, moving=None, fmt='itk'): """Concatenate linear transforms.""" from nitransforms.linear import load as load_affine from nitransforms.manip import TransformChain xfm = TransformChain( [load_affine(f, fmt=XFM_FMT[Path(f).suffix]) for f in in_files] ).asaffine() if reference is not None and not xfm.reference: xfm.reference = reference xfm.to_filename(out_file, moving=moving, fmt=fmt) if out_inv is not None: inv_xfm = ~xfm if moving is not None: inv_xfm.reference = moving inv_xfm.to_filename(out_inv, moving=reference, fmt=fmt)